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• W2014706761 endingPage "205" @default.
• W2014706761 startingPage "146" @default.
• W2014706761 abstract "We present a new set of model predictions for 16 Lick absorption line indices from Hδ through Fe5335 and UBV colors for single stellar populations with ages ranging between 1 and 15 Gyr, [Fe/H] ranging from -1.3 to +0.3, and variable abundance ratios. The models are based on accurate stellar parameters for the Jones library stars and a new set of fitting functions describing the behavior of line indices as a function of effective temperature, surface gravity, and iron abundance. The abundances of several key elements in the library stars have been obtained from the literature in order to characterize the abundance pattern of the stellar library, thus allowing us to produce model predictions for any set of abundance ratios desired. We develop a method to estimate mean ages and abundances of iron, carbon, nitrogen, magnesium, and calcium that explores the sensitivity of the various indices modeled to those parameters. The models are compared to high-S/N data for Galactic clusters spanning the range of ages, metallicities, and abundance patterns of interest. Essentially all line indices are matched when the known cluster parameters are adopted as input. Comparing the models to high-quality data for galaxies in the nearby universe, we reproduce previous results regarding the enhancement of light elements and the spread in the mean luminosity-weighted ages of early-type galaxies. When the results from the analysis of blue and red indices are contrasted, we find good consistency in the [Fe/H] that is inferred from different Fe indices. Applying our method to estimate mean ages and abundances from stacked SDSS spectra of early-type galaxies brighter than L, we find mean luminosity-weighed ages of the order of ~8 Gyr and iron abundances slightly below solar. Abundance ratios, [X/Fe], tend to be higher than solar and are positively correlated with galaxy luminosity. Of all elements, nitrogen is the more strongly correlated with galaxy luminosity, which seems to indicate secondary nitrogen enrichment. If that interpretation is correct, this result may impose a lower limit of 50-200 Myr to the timescale of star formation in early-type galaxies. Unlike clusters, galaxies show a systematic effect whereby higher order, bluer, Balmer lines yield younger ages than Hβ. This age discrepancy is stronger for lower luminosity galaxies. We examine four possible scenarios to explain this trend. Contamination of the bluer indices by a metal-poor stellar population with a blue horizontal branch cannot account for the data. Blue stragglers and abundance-ratio effects cannot be ruled out, as they can potentially satisfy the data, even though this can only be achieved by resorting to extreme conditions, such as extremely high [O/Fe] or specific blue-straggler frequencies. The most likely explanation is the presence of small amounts of a young/intermediate-age stellar population component. We simulate this effect by producing two-component models and show that they provide a reasonably good match to the data when the mass fraction of the young component is typically a few percent. If confirmed, this result implies star formation has been extended in early-type galaxies, and more so in less massive galaxies, which seems to lend support to the downsizing scenario. Moreover, it implies that stellar population synthesis models are capable of constraining not only the mean ages of stellar populations in galaxies, but also their age spread." @default.
• W2014706761 created "2016-06-24" @default.
• W2014706761 creator A5013918544 @default.
• W2014706761 date "2007-07-01" @default.
• W2014706761 modified "2023-10-12" @default.
• W2014706761 title "Population Synthesis in the Blue. IV. Accurate Model Predictions for Lick Indices and UBV Colors in Single Stellar Populations" @default.
• W2014706761 cites W1578014112 @default.
• W2014706761 cites W1619205399 @default.
• W2014706761 cites W1620153315 @default.
• W2014706761 cites W173726204 @default.
• W2014706761 cites W1901465083 @default.
• W2014706761 cites W1936409426 @default.
• W2014706761 cites W1965432896 @default.
• W2014706761 cites W1969972434 @default.
• W2014706761 cites W1972363180 @default.
• W2014706761 cites W1974866549 @default.
• W2014706761 cites W1978850795 @default.
• W2014706761 cites W1979257798 @default.
• W2014706761 cites W1979271265 @default.
• W2014706761 cites W1980390881 @default.
• W2014706761 cites W1981358240 @default.
• W2014706761 cites W1981721463 @default.
• W2014706761 cites W1982032918 @default.
• W2014706761 cites W1982688673 @default.
• W2014706761 cites W1982945915 @default.
• W2014706761 cites W1983678655 @default.
• W2014706761 cites W1984644267 @default.
• W2014706761 cites W1985370957 @default.
• W2014706761 cites W1992981875 @default.
• W2014706761 cites W1993051956 @default.
• W2014706761 cites W1994671833 @default.
• W2014706761 cites W1995563190 @default.
• W2014706761 cites W1996641701 @default.
• W2014706761 cites W1997275633 @default.
• W2014706761 cites W1997384998 @default.
• W2014706761 cites W1997681217 @default.
• W2014706761 cites W1998203113 @default.
• W2014706761 cites W1998530401 @default.
• W2014706761 cites W1999645097 @default.
• W2014706761 cites W2002113271 @default.
• W2014706761 cites W2002281421 @default.
• W2014706761 cites W2003236861 @default.
• W2014706761 cites W2003735032 @default.
• W2014706761 cites W2003742355 @default.
• W2014706761 cites W2004366976 @default.
• W2014706761 cites W2011198720 @default.
• W2014706761 cites W2011424576 @default.
• W2014706761 cites W2013789796 @default.
• W2014706761 cites W2014958365 @default.
• W2014706761 cites W2015295900 @default.
• W2014706761 cites W2017524870 @default.
• W2014706761 cites W2018259295 @default.
• W2014706761 cites W2020566995 @default.
• W2014706761 cites W2022156799 @default.
• W2014706761 cites W2024475525 @default.
• W2014706761 cites W2026714179 @default.
• W2014706761 cites W2026911952 @default.
• W2014706761 cites W2027924499 @default.
• W2014706761 cites W2028733618 @default.
• W2014706761 cites W2029965202 @default.
• W2014706761 cites W2031061612 @default.
• W2014706761 cites W2031411471 @default.
• W2014706761 cites W2031989565 @default.
• W2014706761 cites W2032753227 @default.
• W2014706761 cites W2034723625 @default.
• W2014706761 cites W2041752480 @default.
• W2014706761 cites W2042849210 @default.
• W2014706761 cites W2043123488 @default.
• W2014706761 cites W2047798125 @default.
• W2014706761 cites W2053384007 @default.
• W2014706761 cites W2053628378 @default.
• W2014706761 cites W2053983090 @default.
• W2014706761 cites W2054460092 @default.
• W2014706761 cites W2055468842 @default.
• W2014706761 cites W2057231184 @default.
• W2014706761 cites W2060265136 @default.
• W2014706761 cites W2060275125 @default.
• W2014706761 cites W2062472109 @default.
• W2014706761 cites W2062966120 @default.
• W2014706761 cites W2065234066 @default.
• W2014706761 cites W2065755802 @default.
• W2014706761 cites W2069648733 @default.
• W2014706761 cites W2070304421 @default.
• W2014706761 cites W2070543749 @default.
• W2014706761 cites W2070599935 @default.
• W2014706761 cites W2073956619 @default.
• W2014706761 cites W2074005802 @default.
• W2014706761 cites W2077753988 @default.
• W2014706761 cites W2080837763 @default.
• W2014706761 cites W2082735313 @default.
• W2014706761 cites W2083805862 @default.
• W2014706761 cites W2084178876 @default.
• W2014706761 cites W2086348625 @default.
• W2014706761 cites W2087410577 @default.
• W2014706761 cites W2090418808 @default.
• W2014706761 cites W2091685842 @default.
• W2014706761 cites W2092131964 @default.
• W2014706761 cites W2095777814 @default.

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